Due to the nature of the RARAF microbeam, sub-cellular targets such as the cell nucleus or the cell cytoplasm have been possible for years. With a sub-micrometre diameter beam routinely available, additional targets within cellular systems are accessible. For instance, preliminary radiation experiments that target mitochondria have been conducted on small airway epithelial cells. Point and shoot microbeam During microbeam irradiation, cells to be irradiated are moved to the beam position using a high-speed high-resolution three-axis piezo-electric stage. In order to further reduce targeting time, and making use of the fact that a focused microbeam, unlike a collimated one, is not restricted to a single location on the accelerator exit window, we have implemented a magnetic-coil-based fast deflector, placed between the two quadrupole triplets, that allows deflecting the beam to any position in the field of view of the microscope used to observe the cells during irradiation. Moving the beam to the cell position magnetically can be performed much faster than moving the stage. The deflector used in this system can move the beam to as many as 1000 separate locations per second—more than 5 times the speed of movement of the stage—dramatically reducing the irradiation time. X-ray microbeam The RARAF microbeam is adding an x-ray microbeam using characteristic Kα x rays from Ti. The x rays will be generated using an electrostatic lens system to focus protons onto a thick Ti target. The x rays generated are demagnified using a zone plate. By using the already focused proton microbeam to generate characteristic x rays, it is possible to obtain a nearly monochromatic x-ray beam (very low bremsstrahlung yield) and a reasonably small x-ray source (~20 µm diameter), reducing the requirements on the zone plate. There are considerable benefits in using soft x-ray microbeams for both mechanistic and risk estimation end-points. The higher spatial resolution achievable with modern state-of-the-art x-ray optics elements combined with the localized damage produced by the absorption of low energy photons (~1 keV) represents a unique tool to investigate the radio-sensitivity of sub-cellular and eventually sub-nuclear targets. Also, since low-energy x rays undergo very little scattering, by using x rays with an energy of ~5 keV it will be possible to irradiate with micrometre precision individual cells and/or parts of cells up to a few hundred micrometres deep inside a tissue sample in order to investigate the relevance of effects such as the bystander effect in